Answer:
Step-by-step explanation:
10m^2 and 15mk
common factor is 5m
HCF is 5m
a=0, b=-4
a+b=-4.....(1)
a-b=4.......(2)
(1)+(2): 2a=0
a=0
0+b=-4
b=-4
(a, b) =(0,-4)